1. Field of the Invention
Aspects of this invention relate generally to baby monitors, and more particularly to a baby monitoring system for measuring the breath rate and body orientation of a child or infant using accelerometer technology.
2. Description of Related Art
Baby monitors are well known. Such monitors typically comprise either video cameras and/or audio microphones that are placed in close proximity to the child which transmit a signal to a remote video monitor and/or speaker to thus provide the supervising caregiver with a visual and/or audio signal to the alert the caregiver that the child is uncomfortable or in distress. With respect to most prior art auditory systems that Applicants are aware of, such systems are designed to merely reproduce the sounds emanating from the child, such as crying, coughing and/or choking, which serve as the basis to warn the supervising caregiver that attention is needed.
Although generally effective in monitoring the condition of a child from a remote location, most prior art systems currently in use suffer from numerous drawbacks. With respect to video monitoring systems, it is known that the cameras utilized are typically mounted in a fixed position and can only monitor a limited area. As such, to the extent the child strays from that field of vision, or is covered in bedding, these video monitoring systems are ineffective. Similarly, acoustic monitoring systems suffer from the drawbacks of not providing consistent, uniform and dependable monitoring of a child. In this regard, such systems are based upon the child producing an audible signal when in distress or discomfort. However, such systems fail to address a number of situations where a supervising caregiver must necessarily be warned about conditions beyond those sounds generated in the child's environment. For example, such audio monitors fail to provide any indication should the child quietly leave their bed or simply stop breathing, which occurs with Sudden Infant Death Syndrome (SIDS) where a healthy infant dies suddenly during sleep, for no apparent reason. Accordingly, there is a strong need for a child monitoring system which can detect the physiological presence of a living child/infant.
The following art defines the present state of this field:
U.S. Pat. No. 4,146,885 to Lawson, Jr. discloses a hospital bed or mattress for neonatal infants with a respiration monitor and alarm to detect apnea. No sensor or other appliance is attached to the infant. The bed comprises a base or frame structure with a soft resilient membranous top or cover, e.g., of sheet rubber. The closed air space below the pan is vented to the outside as by a small hole or tube, the average air pressure inside being about atmospheric. The baby's breathing causes slight rhythmic displacements of portions of the body, which in turn transmit small dynamic “recoil” forces proportional to acceleration to the flexible membrane on which the baby rests. The resulting diaphragm-like displacements modulate the air pressure inside. Breathing is sensed by monitoring this acoustic signal by a vented pressure microphone or by sensitive anemometer means connected to the vent. Acoustic and electrical filtering are used to discriminate against higher-frequency signals from the heart-beat and from ambient vibration. Cessation of the respiration signal for a predetermined period of time actuates an alarm.
U.S. Pat. No. 5,022,402 to Schieberl et al. discloses a medical monitoring device which monitors the pulse and respiration rate of an infant, and transmits an alarm signal to a remote receiver when pulse and/or respiration rate irregularities are detected. The device incorporates an acoustic sensor (microphone) and pressure sensor adjacent a small gas or liquid-filled bag or bladder member. The bladder member and attached sensors are contained in a compact monitor housing which is positioned against the monitored infant's body, so that the bladder member directly contacts the body, and is preferably held in place by a small belt wrapped around the infant.
U.S. Pat. No. 5,515,865 to Scanlon discloses a movement and sound monitor and stimulator which is particularly useful for preventing death in human infants from sudden infant death syndrome. The movement and sound monitor and stimulator has a base member which may be a fluid-filled sensing pad for supporting the infant or other animate object which is being monitored and a transducer positioned for detecting movement or acoustic activity (e.g., heartbeat, breathing) of the object on the base member to provide an output signal in response to forces applied thereto which are generated by such movement. A circuit is connected to monitor the output signal from the transducer and activates a stimulator which is operable to provide movement to the base member to stimulate movement in the object when output from the transducer to the circuit corresponds to no movement from the object. The transducer may be a pressure transducer in fluid communication with the fluid interior of the sensing pad. In the alternative, a piezo-electric sheet operatively connected to a surface of the sensing pad to detect such movement as well as movement cessation. The circuit may also be connected to an alarm which can provide an audible or visual indication to third parties when there is no movement from the object.
U.S. Pat. No. 5,684,460 to Scanlon discloses a movement monitor and stimulator which may prevent death in human infants from sudden infant death syndrome (SIDS). Recent medical studies indicate a SIDS victim's breathing may be resuscitated by immediate stimulation. The sound and/or movement monitor and stimulator may have a base member configured as a fluid-filled sensing pad for supporting an infant and a transducer for detecting movement or acoustic activity (e.g., heart beat, breathing, voice and motion sounds). A stimulator may move the base member to stimulate movement in the object when output from the transducer corresponds to no sound and/or movement from the object, or indicates a dangerous change in monitored condition, such as the decrease in metabolic rate indicative of the onset of sleep. The stimulator may also be applied in a more gentle fashion to soothe and quiet an infant that has been awakened unexpectedly. The transducer may be a pressure transducer in fluid communication with the fluid interior of the sensing pad. Alternatively, a piezoelectric sheet operatively connected to a surface of the sensing pad may detect movement and movement cessation. An alarm may provide an audible and/or visual indication to third parties when there is no movement from the object. A transmitter may continuously transmit the sensor's output to a remote location for monitoring. A remote monitor may transmit heart and breathing sounds and may also have lights indicating motion and acoustic activity to indicate the infant is breathing.
U.S. Pat. No. 6,011,477 to Teodorescu et al. discloses a monitoring system which includes a first sensor for detecting the respiration and/or movements of an infant, and an optional second sensor for detecting the presence and/or movement of the infant or proximal objects surrounding the infant. An optional accelerometric sensor detects movements of a platform supporting the infant and contributes supplementary movement data to the monitoring system. An optional audio sensor detects sounds associated with the infant or proximal objects. None of the sensors are physically attached to the infant. A controller conditions and processes the various sensor signals and generates alarms by interpreting the sensor signals. The controller optionally communicates with a remote control unit. In one embodiment the first sensor signal is filtered to extract respiration- and nonrespiration-related signals that are processed by a signal processor, which compares the extracted signals to thresholds, and if neither signal exceeds its threshold for a predetermined time, a low signal alarm is generated. In another embodiment, the signal processor determines whether a respiration decay period is less than a threshold value, and if not, generates a respiration decay alarm. In yet another embodiment, the signal processor compares the respiration-related signal pattern to a stored pattern, and if the patterns do not match, a respiration pattern alarm is generated. The signal processor further interprets various combinations of the sensor signals and makes aggregated decisions to generate specific warnings when critical situations occur.
U.S. Pat. No. 6,150,941 to Geiger et al. discloses a stand-off, non-invasive acoustic detector for monitoring physical activity and/or breathing activity of children and infants. According to a preferred embodiment, the present invention comprises a two-phase output oscillator coupled to an ultrasonic transmitter and microphone. A respective one of the outputs of the oscillator drives the ultrasonic transmitter, through a power amplifier, which sends out an ultrasound wave. The echo return is picked up by the microphone and thereafter band passed to isolate those frequencies falling within 33 to 40 kHz. Such signal is further adjusted for automatic gain control. The resultant echo return signal is compared to the respective other output of the oscillator, the latter also being adjusted for automatic gain control, which are then combined via a summing junction to produce a resultant signal, the latter being utilized to drive a phase comparator and an alarm timer. To the extent the resultant signal, which corresponds to continuous breathing activity or physical activity, deviates substantially from the signal produced by the comparator for a sufficient length of time, an alarm is activated to signal either abnormal breathing activity or a lack of breathing activity, the latter indicative of either a medical condition, such as SIDS, or the absence of the child from the monitored area.
U.S. Pat. No. 6,485,441 to Woodward discloses a mattress device which provides a high information variety from a low number of sensors configured and placed in correspondence with a mattress core layer and a mattress top layer of the mattress device in order to monitor a patient's sleep behavior. Mattress core and top layers provide a static position transmission characteristic and a dynamic impulse transmission characteristic enabling the sensors to recognize body imprint position and body impulses induced by the sleeping patient with a broad bandwidth. In an alternate embodiment, the mattress device may be combined with a signal coder capable of receiving signals or signal components from the sensors and transform them in an analog signal that can be received and processed by a conventional sound card of a computer. A decoding program installed on the computer decodes the alphanumeric information processed from the analog signal by the sound card and makes it available for further interpretation.
U.S. Pat. No. 6,847,892 to Zhou et al. discloses a remote device that includes a sensor for determining or measuring a desired parameter, a receiver for receiving position data from the Global Positioning System (GPS) satellite system, a processor for determining whether or not alert conditions are present and a wireless transceiver for transmitting the measured parameter data and the position data to a central station, such as an application service provider (ASP). The ASP, in turn, may communicate the measured data, position data and notification of any alerts to an end user via an alert device. The present invention also relates to various applications and systems utilizing the capabilities of such a device.
U.S. Patent Application Publication No. 2005/0277842 to Silva discloses a monitor respiration movements device to be used on humans and also on animals for controlling the respiration movements and specially to control the apnea periods on infants. Furthermore the present invention is related to reduce the mortality rate caused by the sudden instant death syndrome (SIDS). The device comprises an accelerometer and a micro controller, said accelerometer includes a motion detector and a plurality of output plugs, said micro controller includes a plurality of input sockets, wherein said plurality of output plugs are connected so said plurality of input sockets and the micro controller includes signal outputs which are connected to an alarm means.
U.S. Patent Application Publication No. 2007/0296571 to Kolen discloses techniques and systems that monitor motion of a person or object and wirelessly communicate the motion data of the person through a network of wireless communication transceiver nodes to a central monitor station. An abnormal state of motion of the person or object can be detected based on the motion data and an alert signal can be generated when an abnormal condition of the person or object occurs. Other parameters of a person or object may also be measured and transmitted to the central monitor station, such as the heart beat and body temperature of the person or the orientation or dynamic motion of an object.
U.S. Patent Application Publication No. 2008/0015457 to Silva discloses a monitor respiration movements device to be used on humans and also on animals for controlling the respiration movements and to control the apnea periods on infants, wherein the device reduces the mortality rate caused by the sudden instant death syndrome (SIDS), wherein the device comprises an accelerometer and a micro controller, with the accelerometer including a motion detector and a plurality of output plugs, the micro controller includes a plurality of input sockets, and wherein the plurality of output plugs are connected to the plurality of input sockets and the micro controller includes signal outputs which are connected to an alarm.
U.S. Pat. No. 7,420,472 to Tran discloses a monitoring system which includes one or more cameras to determine a three dimensional (3D) model of a person, means to detect a dangerous condition based on the 3D model, and means to generate a warning when the dangerous condition is detected.
U.S. Patent Application Publication No. 2008/0252445 to Kolen discloses techniques, apparatus and wireless sensing networks for using wireless sensor modules positioned at different locations to obtain data of a person, an object or a premise and to form a dynamically configurable wireless sensing network where each wireless sensor module is wirelessly connected to the network and can be automatically added to or removed from the wireless sensing network.
U.S. Patent Application Publication No. 2008/0262381 to Kolen discloses techniques, devices and systems that monitor the orientation and breathing of an infant and wirelessly communicate the orientation/breathing data to a caregiver through a wireless interface to request intervention if an unsafe situation is detected.
U.S. Patent Application Publication No. 2008/0294019 to Tran discloses a monitoring system which includes wireless local area network (WLAN) transceivers operating as a Doppler radar to wirelessly detect the person's heart parameter, and a processor coupled to the WLAN transceivers to determine a stroke attack.
U.S. Patent Application Publication No. 2008/0319282 to Tran discloses a monitoring system for a person in a building which includes a plurality of wireless bases positioned in the building, a body mounted temperature sensor, a body mounted heart signal sensor, a wearable device coupled to the temperature sensor and to the heart signal sensor and having a wireless transceiver adapted to communicate with the wireless bases, and an accelerometer.
The prior art described above teaches baby monitoring devices and systems configured for measuring the breath rate and/or body orientation of a child using various technologies, including accelerometer technology. However, the prior art fails to teach such a system that provides at least two tri-axial accelerometers positioned on the child's body and configured such that each accelerometer is independently capable of measuring both the child's breath rate and body orientation, even where the child's body is oriented such that movement of at least one of the accelerometers is restricted. Additionally, the prior art fails to teach such a system capable of recording and reproducing a heart beat sound of the child's mother. Aspects of the present invention fulfill these needs and provide further related advantages as described in the following summary.